Police in mainland China have dismantled a coordinated, months-long smear campaign targeting major e-commerce platforms Alibaba Group Holding and JD.com, as Beijing continues to facilitate fair competition and improve the environment for the private sector.

Both companies publicly praised the police in Chengdu, capital of China’s southwestern Sichuan province, for “combating online rumours” and “maintaining a clean and healthy online environment”, according to social media posts last week by JD.com and Taobao Shangou, the instant commerce unit of Alibaba.

The Taobao Shangou post specifically said that the false information included fabricated images of uniforms of its food delivery couriers with altered text on the clothes to imply that the platform offered illegal services.

JD.com, which did not specify what the smears were about, said they targeted not only its food delivery operations but also its finance unit and its founder, Richard Liu Qiangdong.

JD.com and Alibaba pointed to the alleged involvement of Chengdu Xiaoben Culture Media, a media agency hired by an unnamed company to conduct the online attacks. Neither company identified who was behind Chengdu Xiaoben’s campaign. Alibaba owns the South China Morning Post.

The public security authority in Sichuan announced the case earlier this month, stating it had imposed administrative penalties on five individuals from the agency. It added that it handed the relevant evidence to market regulation authorities for further investigation.